Product · Materials Science
Product · InnDex 62 · Evidence provided · High specification risk
Portland cement-free structural concrete using GGBS and fly ash with alkali activation.
EFC is a geopolymer concrete that eliminates Portland cement entirely, replacing it with ground granulated blast furnace slag and pulverised fly ash activated by alkaline compounds derived from industrial waste. It directly addresses embodied carbon in structural concrete, a critical whole-life carbon lever in buildings. Deployment evidence includes a 232 m³ pour on HS2 Euston (76 tonnes CO2 saved) and a 736 m³ continuous pour for National Grid London Power Tunnels.
EFC eliminates Portland cement entirely, replacing it with GGBS and pulverised fly ash activated by alkali compounds from industrial waste streams, and delivers documented embodied carbon reductions of 60–80% against standard OPC concrete — numbers that place it among the most consequential structural material levers available to a design team chasing whole-life carbon targets under Part Z or PAS 2080 obligations. The deployment evidence is the strongest card: a 232 m³ in-situ pour on HS2 Euston saving 76 tonnes of CO2, followed by a 736 m³ continuous pour for National Grid's London Power Tunnels, demonstrates real-world capability on major infrastructure at scale rather than controlled trials. The qualifications are specific rather than vague. Longer curing times and temperature sensitivity require thermal management during setting that adds on-site complexity and constrains placement windows — this is a workability constraint the structural engineer and contractor programme must accommodate explicitly, not absorb passively. Long-term durability data beyond roughly 20 years in UK exposure conditions is limited because widespread deployment is recent, and the alkali activator supply chain and consistent GGBS/fly ash quality are not yet mature at national scale. Material cost premium over OPC concrete has not been offset by carbon savings in most projects, and building code acceptance for geopolymer structural concrete is still developing. For infrastructure and civic projects with a firm carbon brief and the contractor capability to manage curing protocols, EFC is arguably the highest-impact single material choice available in structural concrete; for volume housebuilding or cost-constrained commercial work, the premium and programme implications need to be resolved before the carbon benefit translates to a viable specification.
Two named large-scale pours (HS2, National Grid) are documented in public UKGBC resource, providing credible deployment evidence. A PCF Declaration under ISO 14067:2018 exists and is certified by The Footprint Company—this is a material-level carbon claim, not a full cradle-to-grave EPD per EN 15804. No full EN 15804 EPD found in public sources; this is a notable gap for UK construction specifiers and tender compliance. Capital Concrete QSRMC accreditation is noted but not independently verified in this review. Wagners (Australian parent) geopolymer technology is established; UK-scale replication and supply chain maturity are less proven. Long-term durability data (>10 years in-situ) not cited in source material.
#embodied-carbon #geopolymer #cement-free #waste-valorisation #structural-concrete #decarbonisation